Method and device for setting up a virtual electronic teaching system with individual interactive communication

ABSTRACT

A method and device for setting up a virtual electronic teaching system with individual interactive communication is proposed. Various methods and devices for carrying out tele-teaching or e-learning sessions have been previously suggested. These methods and devices are improved in such a manner that work stations that can be freely interlinked and individual interactive communication can be set up at low cost. Towards this end, a telecommunication network is used that comprises a main distribution frame linked with an exchange (VST). An access multiplexer and/or a splitter are connected to the main distribution frame or are integrated into the main distribution frame. analog or digital telecommunication systems (TE) are connected via an interface circuit (SS). When the connection is set up, at the transmitter end, the kind of connection available to the interface circuit (SS) is determined. A stored test information is transmitted to the remote station and a receipt, received from the remote station in the return direction, is evaluated, wherein the bandwidth available on the telecommunication system (TE) is tested. The system is particularly useful in the field of electronic teaching.

This application is the national stage of PCT/EP2004/009303 filed onAug. 19, 2004 and claims Paris Convention priority of DE 103 39 436.2filed Aug. 24, 2003.

BACKGROUND OF THE INVENTION

The present invention primarily concerns a method for setting up avirtual electronic teaching system with individual interactivecommunication. Furthermore, the present invention concerns device forsetting up a virtual electronic teaching system for implementation ofthe method.

The areas of e-learning, tele-teaching and remote-training, as well asareas of internal training and further education, training of serviceunits, etc., are generally defined by the fact that users from verydifferent educational backgrounds and with varying technical equipment(computers and periphery) come together for a defined time in definedteaching events.

The majority of connections to the Internet or to other data services isestablished by means of modems via telephone cable, i.e. a double copperconductor (so-called a/b pair or subscriber line), which originally wasintended for the purpose of voice transmissions from about 300 Hz to3400 Hz (POTS). In order to guarantee the highest level of transmissionsecurity, the existing analog transmission technology is replaced to anincreasing extent by digital transmission technology. For this purpose,systems working according to the standard of “Integrated ServicesDigital Network” (ISDN) are predominantly being used in wirecommunication technology.

With the aid of a frequency separating filter, for example, a splittermatrix, voice and data are separated, as a rule, by means of passivelow-pass and high-pass filters and fed into the telephone wire (forexample, for a DSL transmission process). The voice communications aretransmitted to a classic exchange, which is referred to as a so-calledPSTN (Public Switched Telephone Network), and the data are transmitted,after the splitter, to a DSLAM (Digital Subscriber Line AccessMultiplexer—a device that converts the signals from several DSL linesinto a broadband channel). Therefore, it is not possible to draw adistinct separating line between conventional telecommunication networksand computer data networks here. DSL modems, being the most importantelement for a DSL connection, are connected to both ends of theconnection line.

In the DSLAM, for example, it is possible to utilize the ADSL technology(Asymmetric Digital Subscriber Line, an asymmetric DSL data transmissionmethod). This is to be understood as a transmission technology thatallows, at a high bandwidth, Plain Old Telephone Services (POTS) or ISDNfor voice transmission, as well as asymmetric multimedia serviceswithout regenerators on the same pair of wires without disturbances. Itmust be asymmetric (ADSL), because in the direction from the user to thenetwork (upstream), the transmission is relatively low-rate (forexample, at approx. 800 KBit/s), and in the direction from the networkto the user (downstream) it is relatively hi-rate (for example, up toapprox. 8 MBit/s). Aside from the ADSL technology, other DSLtechnologies are in common use, as well, for example, HDSL=High Transferrate Digital Subscriber Line, SDSL=Single Line Digital Subscriber Line,MDSL=Multirate Digital Subscriber Line, RADSL=Low Rate Adaptive DigitalSubscriber Line and VDSL=Very High Rate Digital Subscriber Line, each ofwhich is optimized for their respective applications and which aregrouped under the generic term xDSL transmission technology.

Another possibility being able to transmit continual data flow at lowcosts, for example, voice or video communications, are offered bypacket-switched communication networks, such as LANs (Local AreaNetworks), MANs (Metropolitan Area Networks) or WANs (Wide AreaNetworks). For example, the so-called Internet telephoning is based onthis technology, which is frequently also referred to as “Voice overInternet Protocol” (VoIP). The parallel operation of an audio networkwith a PC network in a teaching system is described, for example, in DE42 38 848 C2. The PC network is intended for visual data transmissionand is wired independently from the audio network consisting ofsingle-board computers as well as D/A converters and A/D converters foraudio transmission. A control computer installed in the central controlmodule of the teacher controls the PC network as well as the audionetwork with one control program [=control software] with a common userinterface for the PC network and the audio network for the coordinationof the simultaneous operation of both networks. Therefore, the centralcontrol module serves the purpose of controlling a PC network as well asthe audio network. The control software also includes monitoringfunctions. For instance, a visual display of the current operatingcondition of the single-board computer, the student's workstation or thestudent's computer on the monitor of the control computer is possible.In addition, the current progress status of work instructions orassignment texts of individual students can also be verified on themonitor of the control computer. A visual display of current operatingconditions of individual components of the control module is possible,as well. The control software also handles voice connections betweenteacher and student. All events occurring during a lesson can berecorded and, in form of an instruction record, can either be savedautomatically on the hard disk of the central control computer orprinted out. Due to the uniform user interface for the PC network andthe audio network, the classroom sheet is always identical in bothnetworks.

Thus, due to the described non-homogeneity, communications take placevia connections with a wide variety of bandwidths, i.e., for example, 56KBit analogue connections or 64 KBit ISDN or DSL or—insofar asintegrated in a LAN—via 100 MBit twisted pair lines, or via dial-upconnections 2 MBit and better, or via dedicated lines X.25.Correspondingly, there are a multitude of known interface devices, forexample:

-   -   ISDN S₀-interfaces,    -   LAN-interface FE (with program memory) to PCI bus,    -   external LAN-interface LAN (with program memory) as 10/100        Mbit/s Ethernet or token ring,    -   WAN-interfaces WAN: X.21, V.35, G.703/704 to 2 Mbit/s.

As far as, on the one hand, contents are available on a content server,which can be accessed via the Internet, and as far as, on the otherhand, communications in form of video conferencing also take place viathe Internet, various different protocols must be observed in thisrespect. For these protocols, based on the Internet protocol (IP), nouniform standard has been established as yet. There are certain“favorites” for certain areas of application (for example, H323 forvideo conferencing or similar).

WO 03/046861 A1 discloses an electronic teaching system, whereas thecommunication between teacher and students takes place via a LAN, whichis connected to a central DVB (digital video broadcasting)-receiverstation with DVB-tuner/receiver, central control unit and mass storageunit. The DVB-tuner/receiver may be designed as a set-top box, whichreceives the DVB information and forwards this information by means of acontrol unit in the form of a PC (personal computer) via the LAN to thecomputer of the teacher. The central DVB-receiver station, withappropriate authorization, can also access certain services from theDVB-service provider via a downward channel of the telecommunicationnetwork.

Furthermore, WO 03/026248 A1 discloses an electronic teaching system,whereas the communication between student and teacher is managed viasubscriber lines by a central control device (there referred to as OLMS,Open Learning Management System). A database with a control device(there referred to as LMS, Learning Management System) is connected tothe central control device, which prevents unauthorized access toprograms and data and corresponding to learning progress controls accessto teaching contents.

Similar designs of an electronic teaching system with accesscorresponding to learning progress and communication via Internet areknown from WO 02/37697 A2 or from WO 02/075694 A1.

Finally, WO 02/097654 A1 discloses an electronic teaching system,whereas the profile of a student is centrally stored, whereas theprofile, aside from learning progress, also includes information on thetechnical equipment of the student including bandwidth limitations ofthe subscriber line. This bandwidth limitation can be specified by thestudent or by the system administrator for a group of students.

The situation described here has resulted in the fact that e-learningand tele-teaching, in spite of the sensible approach of making thedidactic skills and knowledge of lecturers available to a wider audienceoutside the classrooms and lecture halls, as well as also makingelaborately prepared instructions materials available to a larger groupof users, has not been able to gain acceptance on a broader base.

Previously available, predominantly exclusively software-basedsolutions, required a relatively high level of homogeneity with regardto technical equipment and bandwidth available to subscribers and, inaddition, assumed that the corresponding software could be installed forthis purpose on the equipment used by the persons participating intele-teaching or e-learning events.

Due to the above-mentioned time-limitations of these events, but also,in part, due to organizational problems (changes in the EDP-structurewithin an organization), these requirements for homogeneity could onlybe fulfilled with difficulty or not at all. In this respect, it isexactly the possibility of being able to attend a time-limited dedicatedteaching event where the actual benefit of e-learning and tele-teachinglies, in contrast to the necessity of being present during certain timeperiods.

The above discussion of prior art acknowledges differently designedmethods and devices for the implementation of tele-teaching ore-learning events are known. For this purpose, computer networks ornetwork connectivity usually requires special hardware and softwarecomponents with a number of expensive devices specially designed forcommunications, such as communication servers for the connection toanother network (public data network, another LAN or host system), or afile server, which administrates data and makes these available to usersin the network, as well as corresponding network access protocols, forexample, CSMA/CD (Carrier Sense Multiple Access/Collision Detection),Token-Passing (bit pattern as authorization mark) or TCP/IP(Transmission Control Protocol/Internet Protocol). However, littleattention was paid to the user group of students and their existingequipment. That is why there is a lack of practical, cost effectivee-Learning and tele-teaching systems, which would assure individual, inparticular automatically adaptable, interactive communications. This isof particular significance, because the telecommunications and computerindustry must be viewed as extremely progressive anddevelopment-friendly industries, which quickly take up improvements andsimplifications and put them into realization.

The aim of the invention is to improve the generic methods/devices insuch a manner that workstations that can be freely interlinked and thatallow for individual interactive communication can be set up at lowcosts.

SUMMARY OF THE INVENTION

This object is achieved by a method for the establishment of a virtualelectronic teaching system with the use of a telecommunication networkwith a main distributing frame connected to an exchange, in which anaccess multiplexer and/or splitter are connecter or integrated in themain distribution, with analog or digital telecommunication devices andwith an interface circuit connectable to one of these devices, which onthe one hand, is connected via a subscribe line circuit or a subscribermodem and splitter or a network termination and subscriber lines to themain distribution and, on the other hand, to the workstation of theperson participating in the e-Learning or tele-teaching event theinventive method comprising the following steps:

-   -   when the connection is set up, at the transmitter end, the kind        of connection available at the interface circuit is determined;    -   a stored test information is transmitted to the remote station;        and    -   a receipt received from the remote station in the return        direction is evaluated;        whereby the bandwidth available on the telecommunication system        is tested.

Testing of the bandwidth available at a telecommunication device as suchis well known. For example, a facsimile device is known from DE 197 13946 A1, which is able to increase the efficiency and reliability ofcommunications by determining, based on a retransmission condition orconditions which are known through a transmission station or receivingstation, whether or not the transmission rate must be reduced and aretransmission is continued. Moreover, the facsimile device is able toreduce the transmission rate appropriately in order to reduce errors andimprove the efficiency and reliability of communications. For thispurpose, the facsimile device is equipped with a modem, which is able todetermine the transfer rate for image data communication in compliancewith the transmission quality of a communication circuit or line.Further to that, the facsimile device uses a protocol that enables thetransmitter side or the receiver side to perform a decrease procedure toreduce the transfer rate at the start of a control channel used toenable the transmitter side and the receiver side to exchange controlsignals. The control signals comprise an error frame retransmissionfunction and follow a primary channel that is allocated to a datacommunication. Specifically, the facsimile device is equipped with atransfer rate detection function in order to detect the transfer rate atthe time of the retransmission of an error frame, a counter function forcounting the number of retransmission processes taking place at the sametransfer rate, a determination function in order to determine whether ornot the retransmission processes which took place at the same transferrate have been repeated at a frequency corresponding to a pre-selectablenumber, and a control function to execute the decrease process, if theretransmission processes at the same transfer rate has been repeatedcorresponding to the pre-selectable number of times. Moreover, a framequantity detection function is planned, in order to detect the number offrames every time error frames are retransmitted. Based on a G3 standardtransmission control process, the facsimile device is equipped with aswitching condition monitoring function, in order to monitor a switchingcondition or a line condition during an acknowledgment or during thereception of image data, as well as a date change request function. Inthis way, the receiving side can be prompted to transmit a signalfollowing or during the reception of a page of image data, which servesthe purpose of requesting a decrease or increase of the transmissionrate on the basis of switching conditions or line conditions, which arebeing monitored by the switching condition monitoring function.Specifically, the switching condition monitoring function monitors theswitching condition or line condition in terms of the EQM-value, and therate change request function request a rate decrease when the EQM-valueincreases, and requests a rate increase when the EQM-value decreases.Finally, the facsimile device features a table, which lists theEQM-values and transmission rates in a ratio of one-to-one.

Furthermore, DE 101 13 196 A1 discloses a method and device for transferrate collection for serial multiple speed imbedding clock pulsereceivers. In order to collect two or more different transfer rates instable fashion simply and automatically, the first process initiallyuses a statistical check of signal edge placement and timercharacteristics of the incoming data flow, followed by theidentification of a signature, which is allocated to the signal edgecharacteristics, on the basis of signal edge characteristics, andfinally, a determination of the transfer rate with which the data flowis transmitted, on the basis of the identified signature. An alternativeinventive method comprises the following steps:

-   -   supply of a clock pulse signals with an initial transfer rate,        in which the clock pulse signal has clock pulse edges;    -   locking of clock pulse edges with data transition of an incoming        data flow;    -   differentiation between data transitions occurring with even and        uneven clock pulse edges;    -   determining whether or not data transitions on average occur        either with even or uneven clock pulse edges, or whether data        transitions on average occur with even as well as uneven clock        pulse edges; and    -   determining the transfer rate of incoming data on the basis of        where data transitions are occurring.

The system comprises a new phase comparator, which is configured toreceive a data flow transmitted at high speed and emits a message eachtime the data flow contains a data transition. A voltage-controlledoscillator is connected to the phase comparator and supplies a clockpulse signal with clock pulse edges. The clock pulse signal is locked tothe data flow. A transfer rate recording circuit is connected to thephase comparator and receives a series of pulses, which are emitted bythe phase comparator. The data recording circuit determines the transferrate on the basis of received pulses. Specifically, the data recordingcircuit comprises an edge ration detection circuit and a thresholdcircuit, in order to determine the transfer rate on the basis of thetransition density of the data flow over a given period of time.

Furthermore, DE 199 59 179 A1 discloses a method for the dynamic changeof transfer rate adaptation factors in a radio communication system. Toimprove the accuracy of transfer rate adaptation factors, one or more ofthe transfer rate adaptation factors are determined service-specific,the data to be transmitted are processed according to the determinedtransfer rate adaptation factor and entered in a transmission frame, andduring the transmission the transfer rate adaptation factors arecontinually determined and updated. In this process, the adaptationtakes place by means of an additional control loop by way of dynamicvariation of the transfer rate adaptation factors. For this purpose, atransport channel transmitting a bit and/or block error rate is checkedby the receiving or transmitting radio station and, in case of excessivedeviation from a target value, a correction of the respective transferrate adaptation factor is initiated.

Finally, DE 296 23 893 U1 discloses an initialization protocol foradaptive transfer rates and the associated transceiver, in particularfor communications between two Asymmetric Digital Subscriber Line (ADSL)modems. To support the adaptation of transfer rates without a restart,i.e. without renewed execution of all previously executed identificationand initialization steps, the initialization protocol contains a firstphase (PROPOSAL), in which a first transceiver proposes a limited rangeof transfer rate values for the said transfer rate, a second phase(CHANNEL ANALYSIS), executed between the first phase (PROPOSAL) and athird phase (SELECTION), in which the highest transfer rate for thetransmission via a communication connection to a second transceiver ismeasured, and in which is indicated which one of the transfer ratevalues has been selected for the transfer rate, and a fourth phase(CONFIRMATION), in which is confirmed that the selected transfer ratevalue for the transfer rate is used for future transmissions. Prior toexecution of the fourth phase, the first transceiver or the secondtransceiver may announce a new proposal for the transfer rate, whereuponthe first phase is executed again. For this purpose, an announcement ofa new proposal for the transfer rate is based on the results of thesecond phase. If none of the initially proposed transfer rate valuescomes close to the highest supported transfer rate from below, atransceiver may inform the other transceiver of its request to formulatea new proposal. This new proposal may contain the highest supportedtransfer rate and some lower values for the transfer rate, which arealso acceptable to the transceiver that generates the new proposal forthe transfer rate. In this way, a renewed execution of the first, secondand third phase may in the end result in a selected transfer rate thatis correctly adapted to the capacity of the connection line. Thistransfer rate is confirmed in the fourth phase. Thus, should one of thetransceivers for whatever reason not be satisfied with the transfer ratevalues from the first proposal, it may announce a new proposal, eventhough it does not yet know the capacity of the connection.

The method of the present invention has the advantage that a uniformconnection for the purpose of testing the connection line, in particularfor the determination of available bandwidth, is provided. Due to thefact that the test is performed automatically, the teacher and thestudents are relieved from testing the available bandwidth duringstart-up or operation. The test does not even have to be performedon-site, but can be implemented anywhere within the system from anylocation.

Furthermore, this object is achieved by an inventive virtual electronicteaching system using a telecommunication network, which comprises amain distribution connected to an exchange, with an access multiplexerconnected to or integrated in the main distribution and/or a splitter,and analog or digital telecommunication equipment by:

-   -   an interface circuit connectable to the telecommunication        device, which, on one end, is connected via a subscriber line or        subscriber modem and splitter or a network termination and        subscriber lines to the main distribution and, on the other end,        to a workstation of the person participating in the e-Learning        or tele-teaching event, and which tests the bandwidth available        at the telecommunication device.

In comparison to state-of-the-art electronic teaching systems, theteaching system of the present invention offers the advantage that anexpensive preliminary installation is not required, that the interfacecircuit enables a simple expansion or modification of the teachingsystem, including the establishment of new user groups and a significantexpansion of the area of application and that, in particular, theconnection of a new student to the teaching system can be accomplishedimmediately and even by an untrained user. The interface circuit of thepresent invention offers the advantage of enabling, in a surprisinglysimple fashion, an individual conception of the virtual electronicteaching system by the user. In comparison to state-of-the-art systems,the user himself “designs” the virtual electronic teaching system inaccordance with his requirements by means of menu-driven programs, sothat the software functions are not limited and the manufacturer of theinterface circuit of the present invention does not have to—inconsideration of a in interface circuit that can be used as soon aspossible for any purpose—make a selection between associated functions.

Furthermore, it is advantageous in that a decentralized control of atesting process running on the workstation is made possible. It is alsopossible, from any point of the telecommunication network, to performthe tests by means of PC/web server or mobile measuring point (GSM or,in case of higher bandwidths, UMTS), where the network connection mayalso be accomplished via an IP interface (including packet-switchednetwork). If applicable, data serving the purpose of testing andmaintenance of a workstation may also be changed in this way. If thecommands are transmitted from a central workstation (teacher), aparticularly powerful method for the introduction of new functions ormodification of existing functions is available, since the changes needonly be made at the central workstation rather than at all individualworkstations. Moreover, the results are available to teaching personnelimmediately after completion of the test. Based on this, furtherdecisions can be taken quickly, or further connections can becommunicated.

In a further development of the invention, an access authorization isstored in the interface circuit, by means of which the control ofestablishing a connection and the test process is safeguarded againstunauthorized access and the procedure is recorded.

This further development of the invention is advantageous in that thetest or maintenance can only be performed by personnel appointed to thetask. It is also possible to assure access to certain groups ofprocesses by means of various access codes, in order to limitresponsibilities or distribute responsibilities differently withinpersonnel. For example, it is possible to form CUG (closed user groups)via ISDN, so that the previously used method of return call numbers maybe omitted and, for example, a dislocation of the interface circuit doesnot result in a software change.

Further advantages and details are contained in the followingdescription of a preferred embodiment of the invention with reference tothe drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a block diagram of a first embodiment,

FIG. 2 shows a block diagram of a second embodiment of the teachingsystem in accordance with the invention, and

FIG. 3 shows an inventive embodiment of the interface circuit SS, viewedfrom the connection side.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The first inventive embodiment shown in FIG. 1, the interface circuit SSis represented as an autonomous device, which is equipped with its ownmicroprocessor MP, its own EPROM memory SP and, if applicable, its ownhard disk (not shown), as well as corresponding interfaces COM(Component Object Model: Windows based technology providing interfacesand enabling communication between software components), USB (UniversalSerial Bus: serial interface), allowing connection of up to 127peripheral devices (mouse, keyboard, printer, scanner, digital cameras,modems, CD-ROM/DVD drives, telephones, MP3 player, etc.; USB 2.0 allowsdata transfer rates of up to 480 Mbps and therefore is also suitable forthe transmission of video data and for fast hard disks).

The device SS communicates, on the one hand, via a standardizedinterface COM, USB with a microcomputer at workstation AP of the personparticipating in the e-Learning or tele-teaching event (USB, COM1 orsimilar), and on the other hand, with the telecommunication device TEthis person has available.

For this purpose, the device SS first performs a test to verify thebandwidth available at the telecommunication device TE.

The log-in procedure is stored in the memory unit SP of the device SS,which is used by this device SS to establish a connection to the centralcontent server of the tele-teaching event, utilizing a telecommunicationnetwork with a main distribution connected to an exchange, where anaccess multiplexer and/or splitter is connected to or integrated in themain distribution.

Once the connection has been established, the first step is to determinethe type of connection pending at the communication interface (analog ordigital) and then to determine the available bandwidth by transmitting asequence of test signals (which are also stored in the memory unit SP ofthis device SS). The telecommunication device TE may be connected to themain distribution via a subscriber line or subscriber modem and splitteror via a network termination NTBA and the subscriber line AL.

A particularly inventive embodiment is that most common transmissionprotocols, which are based on the IP protocol, are stored in the memoryunit SP of the device SS.

The device SS independently tests the available protocols incommunication with the content server of the tele-teaching event andsets itself up for the protocol offered by the content server.

Another important function of the device consists of the way it preventstypical “time out”-problems by indicating the complete reception of animage file in such a way, that the workstation AP remains connected tothe tele-teaching or e-learning event, even though, for example, thetransmission of high-resolution images with a frame rate of 16 1/sec. isnot possible with a 56 KBit connection.

This feature assures that, as far as the transmitting side is concerned,the participant is still connected, however, the participant will onlybe able to receive and display the audio portion of the information andpossibly part of the image.

For many events, this is not necessarily a disadvantage, because it ispossible, for example, to transmit information to the workstation aheadof time, which can then be used independently (for example, videoinformation will be available) and to have the “live communication” onlywithin the scope of the actual e-learning or tele-teaching event.

Since e-learning and tele-teaching organizers are planning to make thedevice SS available to participants on a loan basis for the duration ofan event or a booked and paid training course, it is also important thatthe device SS is additionally equipped with an electronic signature(access authorization) stored on the memory medium SP. Only thosedevices SS which are approved for the event will be able toindependently establish a connection in the above described way.

Correspondingly, the memory media in question (as a rule, EPROMs) shouldbe exchangeable.

FIG. 2 shows another inventive embodiment in that the device SS islocated between the microcomputer of the participant at workstation APand the telecommunication device TE as described above, but also betweenthe power supply of the participant's microcomputer and a locallyexisting PC network. This makes sense, particularly in cases where,within the scope of a local event (for example, internal training) it isintended to exercise complete remote control of the participant'scomputer, including taking control of the keyboard, the mouse, as wellas corresponding transmission of screen contents from teacher tostudent, back to the teacher and to other participants within a LAN. Forthis purpose, the device SS must be equipped with the appropriateinterfaces (for keyboard, mouse, power supply and graphic adapter,video-/graphic adapter).

Another inventive embodiment consists of providing the device SS,according to FIG. 1 or FIG. 2, with an additional intelligent operatingelement BT for language training. The operating element BT is designedto interpret, for example, voice files which are stored on theparticipant's computer or which are transmitted as a stream within thescope of e-Learning or tele-teaching event, as a so-called “teachertrack” (which cannot be altered by the student) and further to that, torecord exercises by the student, for example, repeating a sample text,on the “student track”. Recordings are stored in both cases on thememory media of the participant's computers, and are replayed using thecomputer's sound equipment. In this case, this voice lab operatingelement BT is connected to the appropriate communication head set(microphone, ear phones), while these inventive embodiment according toFIG. 1 and FIG. 2 are directly connected to the device SS.

The system may be further enhanced by connecting a so-called webcam tothe workstation AP, allowing the participant to present himself in hiscontributions to the discussion, or present an experimental setupprepared by him to the other participants or to an auditorium, if thereis a combination of the presence phase and e-learning and tele-teachingparticipants.

Another inventive embodiment may be that the signature stored in thedevice SS makes it possible to transfer so-called content, which havebeen stored by the organizer of the e-learning and tele-teaching eventon his content server, permanently to the computer of the participant(file or stream transfer for storage on the computer of the participant)making the content available not just temporary within the scope of theevent, i.e. to be visualized and audible only by means of thecorresponding interface of the device without transmission to thecomputer of the participant.

According to another inventive embodiment, the interface circuit SS isdesigned as a plug-in card for a network station (subscriber equipmentTE) or a PC (workstation AP). The plug-in card, in turn, is equippedwith a least one microprocessor MP and a bus interface in form of a LANinterface, where the LAN interface is connected to the network stationor the PC acting as host system via the PCI bus which transmits theprotocol control information. When the card is plugged into the hostsystem, it is detected by the plug-and-play function or by standarddrivers as a LAN card. This automatically accomplishes a “login to thenetwork” or start-up, and even in case of exchange of the interfacecircuit SS of the present invention, “re-programming” is not required.For example, with the software module ICL (Intelligent Connection Layer)there is the possibility of switching between various public networkconnections (ISDN, X.25, dedicated lines, dial-up connections such as FEdialing, C and D networks) as required. Thanks to this modulartechnology, future developments in network technology, for example, GSM,can be integrated seamlessly.

Moreover, through use of the components USV, power supply, hard disk(alternatively flash ROM), cooling fan and housing of the host system,cost savings and expanded functions are possible. The plug-in card usesthe PCI bus only for power supply and as a LAN interface. Should thehost system fail, the interface circuit of the present invention isstill operable, since it continues to receive data through the LAN andpower can still be drawn from the PCI bus after a failure of the hostsystem. This connectivity enables in beneficial fashion the use of theinterface circuit SS in any system with a PCI bus (Sun Ultra, Unix) and,in addition, enhances the operational reliability of the network.

Preferably, the plug-in card is equipped with a call number memory foraccess by authorized users and/or network participants and, depending onthe transmitted call number, the call number is verified and/or theconnection to the authorized caller is established. A breach from publicnetworks can be prevented, for example, by means of ISDN call numberverification. The call number, tamper-free transmitted through theD-channel, is compared to a table with call numbers of authorized users.In case of activated callback function, the interface circuit SSestablishes a connection to the authorized caller. Further securitymeasures may be: IP packet filter, callback, identification control, PAP(password authentification protocol), CHAP (challenge authentificationprotocol) and encryption. Of all the above methods, the last-namedencryption is still the most effective means in data protection for thepurpose of rendering data useless when in the wrong hands: for example,the interface circuit SS can be supplied with an encryption methodaccording to the DES standard.

Fees for dial-up connections are charged according to a time anddistance related pattern. In order to avoid idle times, the interfacecircuit SS automatically breaks the connection in case of inactivity indata communications greater than a preselected waiting time (short hold)and, once data are pending again, restores the connection. With optionalcompression, the data traffic can be reduced.

Finally, the interface circuit SS is able, depending on the bandwidthrequirements, to automatically switch additional communication channels,by means of which a dynamic channel management and bandwidth control, isachieved. Depending on the demand of bandwidth, i.e. depending on thevolume of data to be transported, the interface circuit SS automaticallyactivates additional communication channels. For example, by paralleloperation of all 30 B-channels it is possible to achieve transfer speedsup to 1.92 Mbit/sec.

The hardware concept of the interface circuit SS can be adapted to thevaried established connectivity standards in worldwide networkoperations. FIG. 3 shows an inventive embodiment of the interfacecircuit SS viewed from the connection side. The connectors are numberedas follows: 1: Microphone, 2: Headset, 3: Volume control, 4: Line in, 5:Line out, 6: Connector for operating element, 7: Webcam, 8, 9, 10: USBconnectors (e.g. LAN/TP), 11: TV set, 12: Keyboard, mouse, 13: VGAmonitor, 14: TAE/ISDN/DSL connector, 15: Plug-in power unit (12 V), 16:On/Off switch and 17: Card slot for plug-in card (PCMCIA). Speciallyadapted LAN modules with a choice of BNC, AUI, LWL or twisted pairconnectors connect the interface circuit SS to local token ring andEthernet networks. Access to long distance networks (e.g. ISDN, X.25)and dedicated lines is provided with, in part, multi-channel WANadapters (S_(O), U_(PO), U_(KO), X.21, V.24, V.35). Active WAN adapterscan be used for optimum performance. In the area of ISDN, the protocolsDSS1, 1TR6, NI-1 as well as Fetex 150 are available.

The inventive method, in connection with the interface circuit SS (andits multimedia front end MFE), enables the cost effective establishmentof randomly networked workstations with individual, interactivecommunication via random, wireless or wired networks ortelecommunication networks (for example, UTRAN UMTS Terrestrial RadioAccess Network); this means that the workstations can be freelyinterlinked and individual interactive communication can be set up atlow cost. The iterative process running for this purpose with regard tobandwidth includes all reasonably occurring bit rates, which are storedcorrespondingly, can be used, in particular, in heterogeneous structuresand also allows network monitoring with inclusion of the workstation APand the telecommunication devices TE.

In this way, it is possible for the first time to continue work startedin class at school, at the university or college at home—that is, topractice “blended learning”, linking the presence in the classroom with“self-teaching phases” and, by means of “plug and play” to joinheterogeneous user groups with regard to previous professional training,frequently also concerning EDP skills and with regard to availablecomputer and communication equipment, respectively having the usersthemselves set up their own video conferencing or eLearning environment.Moreover, it is advantageous that the interface circuit SS (Syncobox) ofthe present invention is designed as an autonomous unit (with aconnector for a plug-in power supply) and is suitable for analog, ISDNand DSL connections, that e-learning and video conferencing (connectors:web cam, headset and, if applicable, operating element) is enabled witha TV set and without a PC, the corporate LANs remain unchanged(security), that the interface circuit SS reliably protects eLearningsessions and content against unauthorized use and that “crashes” due toincompatibilities between existing computer installations and addedvideo conferencing and eLearning software (not every problem occursimmediately) or “time-outs” during the session are reliably prevented.

In a further development of the invention it is possible, for example,to start up or remotely start up the operating system of themicroprocessor MP of the interface circuit SS either via a boot prom orvia the integrated LAN interface from the hard disk of the host systemor via the external LAN interface from a random system in the LAN, sothat, after the booting procedure, the interface circuit SS representsan autonomous, communication platform independent of the used operationsystem (for example, WinNT); for TCP/IP and SPX/IPX it is possible toinstall or integrate routing functions (also as LCR: Least Cost Router),etc.

1. A method for establishing a connection between a virtual electronic teaching system having a central content-server for an e-learning or tele-teaching event and a workstation of a person participating in the e-learning or tele-teaching event utilizing a telecommunication network having a main distribution connected to an exchange with an access multiplexer and a splitter or a splitter connected to or integrated in the main distribution and an analog or digital telecommunication device, the method comprising: connecting an interface circuit to the telecommunication device or to the workstation, the interface circuit including a memory unit and a microprocessor; registering the interface circuit to the content-server by means of a log-in procedure stored in the memory unit, the interface circuit registering vicariously for the telecommunications device; establishing a connection between the interface circuit and the content-server vicarious for the telecommunication device connected to said main distribution via a subscriber line or subscriber modem and splitter or a network termination and subscriber lines; determining a type of connection pending on the communications interface of the interface circuit; transmitting at least one stored test signal from the memory unit of the interface circuit to the content-server; evaluating an acknowledgement received by the interface circuit from the content-server in response to the test signal; testing at least a bandwidth available to the telecommunication device using the interface circuit, testing all available protocols in communication with said content-server using the interface circuit as the content-server adjusts itself, adjusting the interface circuit to a protocol proposed by the content-server, and preventing “time out”-problems by emitting a message from the interface circuit confirming the complete reception of an image file from the content-server such that said workstation remains connected to said e-learning or tele-teaching event including during periods when broadband transmission is not possible.
 2. The method of claim 1, wherein said interface circuit a plug-in card for the telecommunication device or the workstation, and wherein depending on the bandwidth demand said plug-in card automatically activates additional communication channels by means of which a dynamic channel management and bandwidth control is achieved.
 3. The method of claim 1, further comprising: storing an access authorization in said memory unit of the interface circuit to secure establishment of the connection and to prevent unauthorized access, and recording the log-in procedure.
 4. A virtual electronic teaching system, comprising: a central content-server for an e-learning or tele-teaching event; a workstation of a person participating in the e-learning or tele-teaching event; a telecommunication network connected to said content-server, the telecommunication network including a main distribution connected to an exchange and an access multiplexer and a splitter or a splitter connected to or integrated in the main distribution; an analog or digital telecommunication device; and an interface circuit connected to the telecommunication device, the interface circuit having a memory unit and a microprocessor, wherein a first end of said interface circuit is connected to the main distribution via a subscriber circuit or a subscriber modem and a splitter or a network termination or subscriber lines and a second end of said interface circuit is connected to said workstation, and wherein the interface circuit is connected via at least a standardized interface vicarious for said telecommunication device and registers itself to said content-server by means of a log-in procedure stored in the memory unit, and automatically tests at least a bandwidth available to the telecommunication device and all available protocols in communication with said content-server as a remote station and adjusts itself to a protocol proposed by said remote station by transmitting at least one test signal stored in the memory unit to said content-server so that said interface circuit prevents “time out”-problems by indicating the complete reception of an image file such that said workstation remains connected to said e-learning or tele-teaching event including during periods when broadband transmission is not possible.
 5. The virtual electronic teaching system of claim 4, wherein the interface circuit further comprises a hard disk and at least one of each a plurality of different conventional plug-type connectors for connecting the telecommunication device to the workstation.
 6. The virtual electronic teaching system of claim 5, wherein the memory unit is an exchangeable read-only memory media.
 7. The virtual electronic teaching system of claim 4, wherein an intelligent operating element is connected to the interface circuit.
 8. The virtual electronic teaching system of claim 4, wherein the interface circuit is a plug-in card for a network station or a PC.
 9. The virtual electronic teaching system of claim 8, wherein the plug-in card comprises at least one microprocessor and a LAN interface, wherein the LAN interface is connected to a PCI bus transmitting control information, and wherein a network station or a PC constitutes a host system.
 10. The virtual electronic teaching system of claim 9, wherein said plug-in card is detected as a LAN card by a plug and play function or by standard drivers when said plug in card is plugged into said host system.
 11. The virtual electronic teaching system of claim 8, wherein said plug-in card comprises a call number memory with a number of participants or network stations authorized to access data, and wherein, depending on a transmitted call number, the call number is verified or the connection is established to the authorized caller.
 12. The virtual electronic teaching system of claim 8, wherein the plug-in card automatically breaks a connection in case of a pause in transmission lasting longer than a preselected waiting time, and restores the connection when data are once again pending.
 13. The virtual electronic teaching system of claim 8, wherein, depending on a bandwidth demand, the plug-in card automatically activates additional communication channels to achieve dynamic channel management and bandwidth control. 